Compliant robot blade for defect reduction

ABSTRACT

Embodiments of substrate transfer robot blades to engage and support a substrate during transfer are provided herein. In some embodiments, a substrate transfer robot may include a blade body having a blade support surface; and a plurality of compliant pads, each comprising a contact surface and an opposite bottom surface supported by the body and arranged to support a substrate when disposed on the substrate transfer robot blade.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent applicationSer. No. 61/878,585, filed Sep. 16, 2013, which is herein incorporatedby reference in its entirety.

FIELD

Embodiments of the present disclosure generally relate to semiconductorprocessing apparatus.

BACKGROUND

Semiconductor substrates are subjected to many different processes inorder to manufacture a semiconductor die on the substrate. Modernsemiconductor processing systems typically integrate a number of processchambers on a single platform to perform sequential processing stepswithout removing the substrate from the processing environment. Forefficiency purposes, a transfer robot may be used to transfer thesubstrates between chambers. In some processing systems, transfer robotsare used to move substrates outside of the processing environment. Asubstrate transfer robot blade associated with the transfer robot may beused to engage and support individual substrates during transfer.

Current substrate transfer robot blades support the substrate onnon-compliant, or rigid, substrate support surfaces. However, theinventors have observed that acceleration of the robot blades in sometransfers result in a force on the substrate which can cause defects inthe substrate.

Accordingly, the inventors have provided an improved substrate transferrobot blade.

SUMMARY

Embodiments of substrate transfer robot blades to engage and support asubstrate during transfer are provided herein. In some embodiments, thesubstrate transfer robot blade includes a body having a blade supportsurface; and a plurality of compliant pads each comprising a contactsurface and an opposite bottom surface supported by the body andarranged to support a substrate when disposed on the robot blade.

In some embodiments, a substrate transfer device comprises a robotcomprising an arm coupled to the robot at a first end; a robot bladecoupled to a second end of the arm, the robot blade comprising: a bodyhaving a blade support surface; and a plurality of compliant padscomprising a contact surface and an opposite bottom surface supported bythe body and arranged to support a substrate when disposed on the robotblade.

Other and further embodiments of the present disclosure are describedbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure, briefly summarized above anddiscussed in greater detail below, can be understood by reference to theillustrative embodiments of the disclosure depicted in the appendeddrawings. It is to be noted, however, that the appended drawingsillustrate only typical embodiments of this disclosure and are thereforenot to be considered limiting of its scope, for the disclosure may admitto other equally effective embodiments.

FIG. 1 depicts a plan view of a substrate transfer robot blade accordingto embodiments of the present disclosure.

FIG. 2 depicts a sectional view of the substrate transfer robot blade ofFIG. 1 taken along line II-II.

FIG. 3 depicts a sectional view of a portion of a substrate transferrobot blade in accordance with an embodiment of the present disclosure.

FIG. 4 depicts a sectional view of a portion of a substrate transferrobot blade in accordance with an embodiment of the present disclosure.

FIG. 5 depicts a sectional view of a portion of a substrate transferrobot blade in accordance with an embodiment of the present disclosure.

FIG. 6 depicts a sectional view of a portion of a substrate transferrobot blade in accordance with an embodiment of the present disclosure.

FIG. 7 depicts a plan view of a portion of a substrate transfer robotblade in accordance with an embodiment of the present disclosure.

FIG. 8 depicts a sectional view of the substrate transfer robot blade ofFIG. 7 taken along line VIII-VIII.

FIG. 9 depicts a sectional view of a substrate transfer robot blade inaccordance with an embodiment of the present disclosure.

FIG. 10 depicts a sectional view of a substrate transfer robot blade inaccordance with an embodiment of the present disclosure.

FIG. 11 depicts a substrate transfer apparatus in accordance with anembodiment of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. The figures are not drawn to scale and may be simplifiedfor clarity. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments of the present disclosure relate to substrate transfer robotblades to engage and support a substrate during transfer and a substratetransfer apparatus having such a substrate transfer robot blade.

FIG. 1 is a plan view of a substrate transfer robot blade, blade 100,comprising a blade body, body 102, a first end 104 adapted for couplingto a transfer robot (e.g., robot 1102, FIG. 11), and a second end 106.The blade 100 has a generally planar blade support surface 202 (asillustrated in FIG. 2) and may have a plurality of passages 108 (3shown) having an axis. Passages 108 are illustrated as passing throughthe blade support surface 202, the blade thickness t, and exiting thebottom surface 204 (i.e., passages 108 are through holes). In otherembodiments, passages 108 may be blind holes only partially through thethickness t of the body 102. The blade 100 may include one or morecutouts (not shown) to reduce the overall weight of the blade.

In the non-limiting embodiment illustrated in FIG. 2, the passages 108may have a constant diameter. In some embodiments, the passages 108 mayhave a varying diameter, for example a tapered diameter or a steppeddiameter. In embodiments having a stepped diameter, the passage 108 mayhave a first diameter at a first portion adjacent to the blade supportsurface 202 and a second diameter at a second portion adjacent to thebottom surface 204.

In a non-limiting embodiment of the disclosed blade 100, a plurality ofcompliant substrate supports, for example compliant pads 300, may besupported by the body 102 and arranged to support a substrate 312 when alower substrate surface 313 is disposed on the blade 100. As illustratedin FIGS. 3 and 4, the compliant pad 300 comprises a contact surface 302to engage and support a substrate 312 and an opposite surface, lowersurface 304. The contact surface 302 may be rounded, such as sphericalas illustrated, or may have any other surface configuration or shape to,for example, provide a desired contact area. The compliant pad 300 maybe smaller than, the same size as, or larger than the passage 108. Thecompliant pad 300 may have a pad axis 314.

The compliant pad 300 may be made from materials compatible with theenvironment in which it is used and the substrate being transferred.Non-limiting examples of suitable materials for the compliant pad 300include one or more of polymer materials, such as polyimide-basedplastics such as Vespel® manufactured by DuPont and polyether etherketone (PEEK); ceramic materials such as titanium nitride (TiN), alumina(Al₂O₃) and silicon carbide (SiC); and metal composites, such asaluminum silicon (AlSi). Surface characteristics of the contact surface302 may be enhanced by coating the compliant pad 300 with coatings suchas diamond-like carbon (DLC) or alumina. In some embodiments, thecompliant pad 300 may comprise an electrically conductive material.

A resilient element, for example a compression spring, such as helicallywound spring 308, may be at least partially disposed within the passage108 such that the helical axis of the helically wound spring 308 isaligned with the passage axis 206. For example as illustrated in FIG. 3,the helically wound spring 308 may be positioned coaxially with thepassage axis 206, with the uppermost coil 316 of the helically woundspring 308 abutting the lower surface 304 of the compliant pad 300, suchthat the lower surface 304 is spaced a distance D from the blade supportsurface 202. The helically wound spring 308 may be fixed againstmovement in at least one direction parallel to passage axis 206 byanchoring a portion of the helically wound spring 308, for example thelowermost coil 318, against movement in at least one direction parallelto passage axis 206. The bottom wall 322 of the passage 108, when ablind passage, may fix the helically wound spring 308 against suchmovement. Alternately, a portion of the helically wound spring 308 mayrest against a step, or another feature, within the passage 108. A forceF directed downwardly (as drawn) parallel to the pad axis 314 wouldcause the helically wound spring 308 to compress, causing displacementof the compliant pad 300 in the direction of the force F.

In some embodiments, at least a portion of a compliant pad 300 isdisposed within a passage 108. For example as illustrated in FIG. 3, aprojection 306 may extend from the lower surface 304 and into thepassage 108 such that the compliant pad 300 is supported in displacementin a direction parallel to the passage axis 206. The pad axis 314 mayalign with the passage axis 206 such that the compliant pad 300 iscentered over the passage 208. The projection 306 may be adjacent to andguided in displacement by the side walls of the passage. Guides (notshown) may be provided to facilitate displacement of the projection 306within the passage 108.

As illustrated, in some embodiments the helically wound spring 308 isadjacent to the wall of the passage 108 and axially aligned with thepassage axis 206. The projection 306 may extend into the axial space 323encircled by the coils, for example at least the uppermost coil 316 andlowermost coil 318. The helically wound spring 308 supports thecompliant pad 300 as above.

Some embodiments may include one or more displacement attenuators,attenuators 310, disposed in the body 102 proximate to the passage 108.The attenuators 310 may include magnets or magnetic materials to reducethe amplitude of the displacement of the projection 306 within thepassage 108. The attenuators 310 therefore also reduce the amplitude ofthe displacement of the compliant pad 300. If magnets are used asattenuators 310, the inventors believe, without being bound by theory,that displacement of the projection 306 and the helically wound spring308 in the varying magnetic field between the magnets causes eddycurrents which causes a drag effect on the moving components.

Alternately, or additionally, attenuators 310 may comprise an energyabsorbing material to absorb and dissipate the impact energy. Forexample, the energy absorbing material could be placed in the passage108 to dampen the motion of the projection 306. An energy absorbingmaterial could also be placed between a portion of the compliant pad 300and the blade support surface 202 to achieve a similar result.

In an alternate non-limiting embodiment illustrated in FIG. 4, theprojection 306 may be adjacent to and guided in displacement generallyparallel to the passage axis 206 by the side walls of the passage. Aresilient element, for example spring 402, may be provided between thelower end 320 of the projection 306 and a support surface of the body,for example the bottom of the passage 108. The resilient element may bea spring, similar to the helically wound spring 308, oriented with thehelix axis perpendicular to the passage axis 206. Alternately, thespring 402 may be a helically wound spring 308 positioned coaxially withthe passage axis 206 and such that the uppermost coil 316 is adjacent tothe lower end 320 of the projection. As above, the lowermost coil 318may be fixed against movement in at least one direction parallel topassage axis 206.

According to some embodiments, a compliant pad 500 comprises a contactsurface 502 to engage and support a substrate 312 and an oppositesurface, lower surface 504. As illustrated in FIG. 5, the lower surface504 at least partially rests upon the blade support surface 202 tosupport the compliant pad 500. A projection 506 extends from the lowersurface 504 and extends at least partially through the passage 108 whenthe lower surface 504 is supported upon the blade support surface 202.Clearance may be provided between the passage 108 and the projection506, or an interference fit may be provided between the passage 108 andthe projection 506. The passage 108 may be a through hole as shown inFIG. 5, or may be a blind hole. If the passage 108 is a blind hole, theprojection 506 may be in contact with the bottom of the passage, or maynot extend to the bottom of the passage.

The compliant pad 500 may comprise one or more of the suitable materialslisted above.

FIG. 6 depicts a compliant pad 600 similar to compliant pad 500. Asillustrated, compliant pad 600 comprises a contact surface 602 to engageand support a substrate 312 and an opposite surface, lower surface 604.The lower surface 604 at least partially rests upon the blade supportsurface 202 to support the compliant pad 600. A projection 606 extendsfrom the lower surface 604 and extends at least partially through thepassage 108 when the lower surface 504 is supported on the blade supportsurface 202. Clearance may be provided between the passage 108 and theprojection 606, or an interference fit may be provided between thepassage 108 and the projection 606. The compliant pad 600 may compriseany of the suitable materials listed above and additionally includes alayer 608 adjacent to one or more layers, layers 610, 612 shown. Thelayers 608, 610 may be the same material or different materials, andlayer 608 may be a metal in some embodiments.

Compliant pads 500 or 600 elastically deform, or deflect, under a forceapplied to their contact surfaces 502, 602, respectively, directedtowards the body 102.

In some embodiments shown in FIGS. 7 and 8, a compliant pad 700 includesa base 702 and a resilient cantilevered arm, arm 704. The base 702comprises a top surface 712 and a generally planar bottom surface 714configured to rest upon the blade support surface 202. The base mayinclude openings, such as holes 710 to facilitate attachment of the base702 to the body 102. The arm 704 is fixed at a first end 706 to aportion of the base 702. A second end 708 is resiliently deformed awayfrom a plane P of the base 702 in a direction away from the base 702 andmay include a contact surface 716 configured to engage and support asubstrate 312.

Under a force applied to the contact surface 716 in the direction of thebody 102, the arm 704 deflects in the direction of the force.

In some embodiments shown in FIG. 9, a compliant pad 900 includes a base902 and a resilient cantilevered arm, arm 904, extending from the base902. The base 902 comprises a top surface 912 and a bottom surface 914configured to rest upon the blade support surface 202. The base mayinclude openings, such as holes 910 to facilitate attachment of the base902 to the body 102. The arm 904 is fixed at a first end 906 to the base902 and free at a second end 908. In some embodiments, an upper surface918 of the arm 904 may lie in the same plane P as the base 902.

The arm 904 may comprise a contact element 920 disposed on the secondend 908 and may include a contact surface 916 configured to engage andsupport a substrate (e.g., substrate 312). In some embodiments, the arm904 is formed of titanium and the contact element 920 may include, forexample, at least 6 microns of titanium nitride (TiN). The TiN layer maybe thermally grown on the second end 908 of the arm 904. In someembodiments, the upper surface 918 of the arm 904 may lie above or belowthe plane P as long as the contact surface 916 of the contact element920 lies above the base 902.

In some embodiments, and as shown in FIG. 10, a compliant pad 1000includes a base 1002 on both ends of a resilient platform 1004. The base1002 comprises a top surface 1012 and a bottom surface 1014 configuredto rest upon the blade support surface 202. The base 1002 may includeopenings, such as holes 1010 to facilitate attachment of the base 1002to the body 102. The resilient platform 1004 is fixed to the base 1002at a first end 1006 and at a second end 1008. In some embodiments, anupper surface 1018 of the platform 1004 may lie in the same plane P asthe base 1002.

The platform 1004 may comprise a contact element 1020 disposed on thesecond end 1008 and may include a contact surface 1016 configured toengage and support a substrate 312. In some embodiments, the platform1004 is formed of titanium and the contact element 1020 may include, forexample, at least 6 microns of titanium nitride (TiN). The TiN layer maybe thermally grown on the platform 1005 at or near a center of theplatform 1004. In some embodiments, the upper surface 1018 of theplatform 1004 may lie above or below the plane P as long as the contactsurface 1016 of the contact element 1020 lies above the base 1002.

Contact elements 920, 1020 including a titanium nitride top layer asdescribed above advantageously provide increased wear resistance anddefect reduction. The inventors have also observed that such contactelements provide a tunable compliance with high temperature resistancebased on the thickness of the titanium nitride layer.

During some segments of substrate transfer, the substrate transfer robotblade accelerates from a first velocity to a second velocity when movingfrom one location to another. When a substrate is supported at rest, forexample on lift pins in a chamber, the substrate is at a velocity of 0relative to the chamber. A substrate transfer robot blade, coupled to atransfer robot, may be used in a segment of a transfer process totransfer the substrate from the lift pins to another location. Duringthe transfer process, the substrate transfer robot blade accelerates thesubstrate from a velocity of 0 to a transfer speed, typically betweenabout 1 mm/sec. to about 8 mm/sec. For purposes of this disclosure,velocity and acceleration will be in relation to a fixed point, such asa point on the ground or on a process chamber.

If the substrate is accelerated in the vertically upward direction, theacceleration causes a force exerted by the substrate against thesubstrate transfer robot blade. The force can be represented by theequation F=ma, where “F” represents force, “m” represents mass, and “a”represents acceleration. In the present case, “m” is the mass of thesubstrate, “a” is the vertical acceleration of the substrate, and “F” isthe force exerted by the substrate upon the substrate transfer robotblade as a result of the acceleration. The inventors have noted that theforce F generated during a typical transfer of a substrate is in somecases sufficient to damage the substrate at the areas of contact betweenthe substrate and the substrate transfer robot blade.

The mass of the substrate is generally fixed based on the size of thesubstrate. Therefore, for a substrate of a given mass, a decrease inacceleration can proportionally decrease the force “F” exerted on thesubstrate during transfer. The acceleration “a” is generally understoodmathematically to be the change in velocity divided by the change intime of the velocity change (i.e., “a”=delta V/delta t). In order todecrease the acceleration “a”, the change in velocity can be decreasedor the time of the velocity change can be increased. For productivityreasons, it is often desirable to transfer the substrate as quickly aspossible. It may be desirable, therefore, to decrease the accelerationby increasing the time of the velocity change.

The inventors noted that during substrate transfers, a substrate issupported initially at rest and accelerated to a transfer speed. If thisis effected on a transfer robot blade with unyielding, or non-compliant,pads, the substrate experiences a change in velocity over a very shortperiod of time, leading to a significant acceleration as describedabove. As the delta t in the expression above approaches 0, the handoffbecomes an impact as the substrate transfer robot blade contacts thesubstrate, leading to defect generation.

However, compliant pads allow the substrate to change velocity from 0 tothe transfer speed over a longer period of time. Therefore, a substratesupported on compliant pads would experience a lesser acceleration, anda proportionally lesser force F. The decreased force F may reduce defectgeneration caused by the impact the same change in velocity over alonger time period.

FIGS. 3-10 depict non-limiting embodiments of a substrate transferblade, blade 100, comprising blade support surface 202 and includingcompliant pads 300, 500, 600, 700, 900, and 1000 that may beneficiallydecrease the acceleration of a substrate 312 on a blade during segmentsof a substrate transfer procedure. For example, the disclosedembodiments may decrease the acceleration of a substrate, and theresultant force at the interface of the substrate and the blade, duringsubstrate transfers.

In FIG. 3, a compliant pad 300 is disposed on a body 102 of a blade 100(FIGS. 1 and 2) and supported by a resilient element, helically woundspring 308. The helically wound spring 308 is configured to fit within apassage 108 in the body 102 such that the projection 306 fits within thehelix between the coils. The length of the helically wound spring 308 issufficient to support the lower surface 304 of the compliant pad 300 adistance D above the blade support surface 202. The helically woundspring 308 and the passage 108 are configured to support and guide theprojection 306 in vertical displacement.

Optional attenuators 310 may lessen the amplitude of the harmonic motionassociated with a mass (such as the substrate 312) on a spring (such ashelically wound spring 308).

FIG. 4 depicts an alternate embodiment in which a resilient element,spring 402, is positioned to abut against the lower end 320 of theprojection 306. The spring 402 may be a helically wound spring, such asa canted coil spring, positioned such that the axis 404 of the helixforms an acute angle A with the blade support surface 202. Asillustrated in FIG. 4, the acute angle A is 0 degrees.

As illustrated in FIGS. 3 and 4, a force F applied to the contactsurface 302 may cause displacement of the compliant pad 300 in thedirection of the force F. This displacement may be resisted by thehelically wound spring 308 of FIG. 3 or the spring 402 of FIG. 4.

Resilient elements, other than helically wound spring 308 and spring402, may be used to support the compliant pad 300 such that the lowersurface 304 is spaced a distance from the blade support surface 202.Non-limiting examples of alternate resilient elements include wavesprings, disc springs (e.g., Belleville springs), torsion springs, orthe like.

In some embodiments, the compliant pad is formed from a compatiblematerial listed above with a hardness such that a resilient element isnot needed. For example, as illustrated in FIG. 5, compliant pad 500 isformed form a material such that the pad body 508 acts as a resilientmember and deflects, or yields, under a force F, generated at thecontact surface 502 as discussed above. The lower surface 504 of thecompliant pad 500 is supported on the blade support surface 202. Aprojection 506 may extend at least partially into passage 108 in thebody. Passage 108 may be a through hole as illustrated and theprojection may extend beyond the bottom surface 204 or may end withinthe thickness of the body 102.

As a blade 100 comprising compliant pads 500 contacts a substrate atcontact surface 502 during a substrate transfer, the pad body 508yields, and the time period during which the substrate 312 changesvelocity from 0 to transfer speed is extended. As described above, avelocity change over an extended time period decreases the acceleration,and proportionally decreases the force F generated at the contactsurface 502 between the substrate 312 and the compliant pad 500.

The compliant pads may be formed from more than one of the compatiblematerials above. For example, compliant pad 600 in FIG. 6 includes alayer 608 of a material between layers 610 and 612 of material. Layers610 and 612 may be formed from the same materials or from differentmaterials, such that the compliant pad 600 has the desired hardness toachieve the results above. In some embodiments, layer 608 is a metal.Similar to compliant pad 500, compliant pad 600 has a contact surface602, a lower surface 604 supported the blade support surface 202, and aprojection 606 extending at least partially into passage 108, which maybe a through hole or a blind hole.

Returning to FIGS. 7 and 8, the base 702 of compliant pad 700 may besupported by blade support surface 202 such that the second end 708 ofthe arm 704 is deformed away from plane P to support the substrate 312on contact surface 716. The arm 704 is configured to yield under theforce F generated as discussed above.

As a blade 100 comprising compliant pads 700 contacts a substrate atcontact surface 716 during substrate transfer, the arm 704 yields, andthe time period during which the substrate 312 changes velocity from 0to transfer speed is extended. As described above, a velocity changeover an extended time period decreases the acceleration, andproportionally decreases the force F generated at the contact surface716 between the substrate 312 and the compliant pad 700.

Returning to FIG. 9, the base 902 of compliant pad 900 may be supportedby the blade support surface 202 such that the second end of the 908 arm904 is deformed towards the blade support surface 202 to support thesubstrate 312 on the contact element 920. The arm 904 is configured toyield under the force F generated as discussed above.

Returning to FIG. 10, the base 1002 of compliant pad 1000 may besupported by the blade support surface 202 such that the platform 1004is deformed towards the blade support surface 202 (i.e., deflects) tosupport the substrate 312 on the contact element 1020. The platform 1004is configured to yield under the force F generated as discussed above.

Any combination of the non-limiting examples of compliant pads 300, 500,600, 700, 900, or 1000 (collectively, compliant pads 1120) may be usedon a blade 100 to achieve the desired results of decreased defectgeneration.

The inventors have also noted that with typical transfer robot blades, aworn or defective substrate support surface needs replacement of theblade itself, leading to extended idle time for the robot, and possiblythe processing system. In the present disclosure, a defective or worncompliant pad may be removed from the blade 100 and replaced withminimal impact on productivity. Compliant pads may also be changed basedon the substrate or processing environment. A softer compliant pad maybe desirable for some substrates or processes, while a harder compliantpad may be desirable for others. Rather than changing the transfer robotblade to accommodate specific needs, with the associated interruption toproduction, the compliant pads in the inventive substrate transfer bladecan be changed quickly to a more suitable compliant pad.

A substrate transfer apparatus may beneficially include a plurality ofcompliant pads as disclosed herein. For example, a substrate transferapparatus 1100 may comprise a robot 1102 comprising a robot arm, arm1104, coupled to the robot 1102 for vertical and rotational displacementat a first end 1106. The arm 1104 may comprise one or more links, forexample first link 1108 and second link 1110 pinned together at 1112. Asecond end 1114 of the arm 1104 may include a wrist 1116 to which thefirst end 104 of a blade 100 is coupled. The blade 100 may include anyof the compliant pads 1120, or combinations thereof, as disclosedherein.

In operation, the substrate transfer apparatus 1100 may be operated suchthat the blade 100 is positioned below a substrate 312 supported atrest, for example on a plurality of lift pins 1118. Through mechanicalmanipulations of the robot 1102 and the arm 1104, the blade 100 israised from a position below the substrate 312 to bring the compliantpads 1120 into contact with the lower substrate surface 313 to transferthe substrate 312 off of lift pins 1118. In doing so, the robot 1102,through the arm 1104 and the blade 100, accelerate the substrate from avelocity of 0 to a transfer speed. As described above, the accelerationresults in a force F at contact points between the substrate 312 and theblade 100. As also described above, the compliant pads 1120 yield to theforce such that the change in velocity of the substrate 312 takes placeover a longer time period, decreasing the acceleration of the substrate312 and proportionally decreasing the force F.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments of the disclosure may bedevised without departing from the basic scope thereof.

The invention claimed is:
 1. A substrate transfer robot blade,comprising: a blade body having a blade support surface and a passageformed in the blade support surface, wherein the passage has a bottomwall above a bottom surface of the blade body; at least three compliantpads each larger in size than the passage in the blade support surface,each pad comprising a curved substrate contact surface and a pad bottomsurface and arranged to support a substrate when disposed on thesubstrate transfer robot blade, wherein at least one of the at leastthree compliant pads has a projection from a pad bottom surface and atleast a portion of the projection is disposed within the passage; and aresilient element disposed at least partially within the passage andconfigured to engage a wall of the passage and a surface of theprojection of the at least one of the at least three compliant pads toenable displacement of the at least one of the at least three compliantpads in a direction generally parallel to a passage axis.
 2. Thesubstrate transfer robot blade of claim 1, wherein at least one of theat least three compliant pads is formed of a polymer material.
 3. Thesubstrate transfer robot blade of claim 1, wherein at least one of theat least three compliant pads further comprises: a base configured forsupport on the blade support surface; and a resilient cantilevered armfixed at a first end to a portion of the base and having a second endresiliently deformed from a plane of the base in a direction away fromthe base, wherein the second end comprises a contact surface.
 4. Thesubstrate transfer robot blade of claim 1, wherein the resilient elementis a compression spring.
 5. The substrate transfer robot blade of claim4, wherein the resilient element is a helically wound spring.
 6. Thesubstrate transfer robot blade of claim 5, wherein an axis of thehelically wound spring is aligned with an axis of the passage.
 7. Thesubstrate transfer robot blade of claim 6, wherein the portion of theone of the plurality of compliant pads comprises a projection extendingfrom a pad bottom surface, wherein the projection at least partiallyextends through a center of the helically wound spring.
 8. The substratetransfer robot blade of claim 6, further comprising a displacementattenuator positioned adjacent to the passage.
 9. The substrate transferrobot blade of claim 8, wherein the displacement attenuator comprisesone or more magnets.
 10. The substrate transfer robot blade of claim 5,wherein the helically wound spring is canted.
 11. The substrate transferrobot blade of claim 1, wherein the blade body includes a plurality ofpassages beginning at the blade support surface and terminating betweenthe blade support surface and the bottom surface; wherein the at leastthree compliant pads comprise a plurality of compliant pads eachcomprising a curved substrate contact surface and a pad bottom surfaceproximate to the blade support surface and arranged to support asubstrate when disposed on the substrate transfer robot blade; andwherein the resilient element is configured to engage a portion of atleast one of the plurality of compliant pads.
 12. The substrate transferrobot blade of claim 11, wherein the plurality of compliant padscomprise an electrically conductive material.
 13. The substrate transferrobot blade of claim 11, wherein the plurality of compliant pads areformed from ceramic.